THE CO-Z MK-IV PLT CONDUCTING A TEST FLT EXHAUSTED FUEL IN 1 TANK AND FAILED TO SWITCH TANKS BECAUSE HE THOUGHT THE ENG FAILURE WAS MECHANICAL.

Narrative

THE FLT WAS PLANNED FOR 30-60 MINS TO PERFORM INFLT ENG TESTS AND TUNING. DEPARTED HOME FIELD WITH 12.5 GALLONS IN L TANK AND 10 GALLONS IN R TANK. WHILE I WAS FOCUSED ON ENG TUNING; THE ENG LOST PWR AND STOPPED. I IMMEDIATELY TURNED TOWARDS ZZZ; ESTABLISHED BEST GLIDE; AND CONTACTED APCH CTL. APPROX 1/2 WAY TO ZZZ; I DIVERTED TO ZZZ1 BECAUSE I WASN'T COMPLETELY SURE I HAD ENOUGH ALT TO GLIDE TO ZZZ. THE LNDG AT ZZZ1 WAS UNEVENTFUL. AFTER LNDG I DISCOVERED THAT DURING THE INFLT TUNING I HAD RUN THE ENG VERY RICH AND HAD USED FUEL AT A MUCH HIGHER RATE AND HAD EXHAUSTED ALL FUEL IN THE L TANK. ENG OUT CAUSE: FUEL EXHAUSTION IN ONE TANK AND FAILURE TO SWITCH TANKS. I WAS TOO FOCUSED ON TUNING THE ENG AND LOST TRACK OF TIME AND FUEL MGMNT. DURING THE INCIDENT; I ALSO FAILED TO TROUBLESHOOT -- FIRST CHKING FUEL AND/OR SWITCHING TANKS. I WAS TOO FOCUSED ON PLTING THE ACFT TO A SAFE LNDG AND HAD CONVINCED MYSELF THAT I HAD MADE AN ERROR DURING TUNING THAT I WOULDN'T BE ABLE TO FIX WHILE INFLT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FOLLOWING: HE DID NOT DECLARE AN EMER BECAUSE HE WAS ABOUT 7 MI FROM THE ARPT AT 7500 FT AND WITHIN EASY GLIDING RANGE.